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Kiwi recovery programmes are proving their worth even though the national population of the threatened bird continues to decline, Conservation Department science officer Rogan Colbourne says.

Mr Colbourne has been part of the BNZ Operation Nest Egg scheme. The Hawke’s Bay group released its 100th young North Island brown kiwi into the Kaweka Ranges on Thursday.

Nationally the kiwi population is thought to be falling by about 6 per cent a year, but Mr Colbourne said local programmes were making a difference, in some cases having increased the local population.

“At Okarito [on the West Coast] they have increased the population from 150 to more than 300,” he said.

In Hawke’s Bay, with a kiwi population of fewer than 1000, the addition of 100 young birds since 2003 was significant. Kiwi lived on average to 40 – and even to 60 – if there were no predators.

In these programmes, eggs are taken from the wild and incubated, then the hatchlings are kept in a predator-proof environment till considered big enough to fend for themselves in the wild.

“There is a 90 per cent hatch rate with these eggs, compared with only 50 per cent in the wild, for various reasons,” Mr Colbourne said.

“Possums can eat the eggs, the adults can damage them accidentally, and there can be bacteria after rainfall.

“Once hatched [in captivity] about 80 per cent reach the sub-adult stage and once they are released about two-thirds survive in the wild, though that varies from area to area.”

Of kiwi hatched in the wild, only about 5 per cent survived to become adults, as predators such as stoats, ferrets and feral cats ate the young birds. Ferrets and dogs could kill adults, and dogs were a particular worry in Northland.

About 15 recovery groups were operating in the North Island, with assistance from DOC and other organisations, Mr Colbourne said.

The Hawke’s Bay group is led by the Environment, Conservation and Outdoor Education Trust.

Spokesman Alastair Bramley said the survival rate for the kiwi released in Hawke’s Bay was about two-thirds overall, but it had been up at 90 per cent till an outbreak of ferret attacks in 2008.

“We haven’t lost any since then,” he said.

Dogs were not such a big problem in Hawke’s Bay because hunters there had to put their dogs through kiwi aversion training before they could register them, Mr Bramley said.

The 100th kiwi has been named Parauri and was released in the Kawekas after a ceremony at the Pan Pac Kiwi Creche, inland from Tutira.

A new study shows that New Zealand’s giant – and now extinct – Haast’s eagle ruled the skies until 500 years ago, swooping down on moa.

Scientists have known about the existence of Haast’s eagle since 1871 based on excavated bones, including bones carved by early Maori, but their behaviour was not entirely clear.

Because of their large size – they weighed up to 18kg with wingspans up to 3m – some scientists believed they were scavengers rather than predators.

Earlier research has indicated the eagle had enough strength in its talons to kill a moa weighing 180kg, attacking at up to 80kph, or even to attack a human child.

The latest study throwing new light on this was published in the Journal of Vertebrate Paleontology.

Researchers Dr Paul Scofield, curator of vertebrates at the Canterbury Museum, and Professor Ken Ashwell of the University of New South Wales used computerised CT and CAT scans to reconstruct the size of the brain, eyes, ears and spinal cord of the Haast’s eagle.

These details were compared to values from modern predatory and scavenging birds to determine the habits of the extinct eagle.

“This work is a great example of how rapidly evolving medical techniques and equipment can be used to solve ancient mysteries,” said Dr Ashwell.

Endangered native birds are at risk of losing their instinct to recognise and flee mammalian enemies when moved between predator-free and predator-filled sites, says a Massey researcher.

Sarah Whitwell, a biology Masters student at Massey’s Institute of Natural Resources in Albany, designed an experiment using a pulley system to dangle a stuffed stoat and morepork at nesting North Island robins to test their fear responses. She says most robins in areas free of introduced predators such as stoats failed to get into a flap at the sight of an enemy, albeit a fake version.

Her research adds to growing evidence that native birds’ responses to mammalian predators are not genetically hard-wired.

“That’s because introduced mammal predators have been here a relatively short time, whereas native birds have been here for millions of years.”

She says already endangered native bird species would be at increased risk if moved back to wilderness sites with mammalian predators after inhabiting mammal-free conservation areas without some form of predator-recognition training.

The responses of robins in predator-controlled Wenderholm Reserve and Tiritiri Matangi Island near Auckland were compared with those in the central North Island, where the birds have long co-existed with native and introduced predators.

15 rare Wellington green geckos, seven of which have spent the last twelve months on ‘sabbatical’ at the city’s Karori Sanctuary, are being released on the island on Friday 15 November as part of an annual translocation programme – the largest to date.

DOC first began translocating green geckos to the island sanctuary in 2006 to create a self-sustaining population on this predator-free island. They have been working with local lizard breeders to ensure a genetically diverse supply of geckos for release on a yearly basis. This year, 16 lucky local school children with a special interest in conservation have been chosen to take part in the release.

‘Establishing a safe population on Matiu/Somes will help ensure survival’, said DOC biodiversity ranger Brent Tandy.

Local lizard enthusiasts and conservation projects like Karori Sanctuary play a critical support role for DOC’s gecko recovery programme in terms of both advocacy and breeding. One year old animals are taken to the Sanctuary for display in a special gecko enclosure before being released on the island at two years old.

A big jump in the number of tui visiting Hamilton is predicted next year as the impact of a successful breeding project kicks in.

Environment Waikato expects a bumper tui breeding season at its Hamilton Halo project sites this spring, thanks to a highly successful winter of pest control operations. This is expected to produce results by next winter.

EW aims to attract more tui to the city by wiping out the birds’ two main predators – ship rats and possums – at breeding sites near the city.

It is currently controlling the pests at one Whatawhata site and two sites near Cambridge, Maungakawa Scenic Reserve and Te Miro Reserve. There is around 850 hectares of native bush under protection.

The regional council devised a special pest control programme to kill the rats using more than 1300 bait stations across the three sites.

Pest control took place in August and September, before the October tui breeding season.

EW councillor Paula Southgate said the results of a recent rat census were excellent, with only 2.2 per cent of the 225 tracking tunnels registering rat footprints, compared with up to 41 per cent before pest control.Estimates from Landcare Research were that nesting success could increase from around 25 per cent to 75 per cent.

There were also reports that native seedlings were flourishing on the forest floor without possums and rats around. Other native birds, such as kereru and bellbirds, are also expected to benefit from the programme.

An island sanctuary for rare birds has been at the centre of a pest scare today. Motuihe Island in Auckland’s Hauraki Gulf has been rat-free for 15 years, but yesterday paw prints were found at several spots on the island.

Jack the dog has been specially trained to smell a rat and today his senses were put to the test.

Jack and his owner, Fin Buchanan, have been training for seven years for a day like today.

But with a camera watching Jack’s every step, finding the Motuihe rat still looked like big weight to bear.

The rogue rat threatened the Department of Conservation’s million dollar plans to release kiwi and other rare birds on the island.

“This is the last thing we needed or expected,” DoC threats officer Ditch Keeling said. “We haven’t had a rat on here for 15 years. It’s really quite bizarre.”

The rat is thought to have come in off a boat and prints had been spotted in five of the island’s 45 tunnels, cunningly built to detect rat-steps.

DoC staff like Mr Keeling had been setting traps through the night.

“You live an adrenaline mode for the first ten days and then you start to get really tired,” Mr Keeling said.

But it was not long before Jack found the elusive rodent.

“Obviously we’re pretty elated,” Ditch Keeling said. “If this is the only rat on the island then we’ve just pulled off the fastest complete eradications ever taken place.”

Close inspection showed the rat was a female. The Department of Conservation will now need to check for signs whether she has ever had babies. And if that is the case, Jack could be making a return trip to the sanctuary.

Thirty threatened Kakaruai birds have been successfully transferred to New Zealand’s newest sanctuary.

Secretary Island, a 8,000 hectare island at the western end of Doubtful Sound in the Fiordland National Park, will be the new home to the Kaharuai, or South Island Robin.

“It’s fantastic, it’s been a big achievement getting to this point,” says Murray Willians from the Department of Conservation.

They say a bird in the hand is worth two in the bush but for DOC it’s the birds in the bush that are important.

“There’s no rodents or possums here, and essentially no stoats and very few deer now too, so it’s essentially clear of introduced animals that cause harm to NZ’s native biodiversity,” says Willians.

The birds were transferred from Breaksea Island following a three year project to rid the island of predators.

Breaksea was the forerunner of the country’s island restoration programme and boasts a population of thousands of Kakaruai, and other threatened species.

Offshore islands play a key role in the battle against introduced pests. Birds like the Saddleback would have been extinct without them.

There used to be thousands of South Island Robins on Secretary Island before Stoats were introduced about a hundred years ago. Now there are none, and DOC is hoping this population of birds brought here, will flourish.

“Seeing and hearing that birdsong and thinking of what it used to be like in the South Island beech forests is quite incredible and quite different to what we see now on the mainland anywhere really,” says Willans.

“These conservation programmes are very important. It’s very important we retain the character of the area,” says John Davies from the Fiordland Conservation Trust.

The programmes will ensure the birds keep singing for generations to come.